If R2 is the resistance of secondary winding of the transformer and K is the transformation ratio then the equivalent secondary resistance referred to primary will be
A. $$\frac{{{{\text{R}}_2}}}{{\sqrt {\text{K}} }}$$
B. $$\frac{{{{\text{R}}_2}}}{{{{\text{K}}^2}}}$$
C. $$\frac{{{\text{R}}_2^2}}{{{{\text{K}}^2}}}$$
D. $$\frac{{{\text{R}}_2^2}}{{\text{K}}}$$
Answer: Option B
Lets eqv secondary resistance=R', current=I'
Given, secondary resistance =R2, current =I2(let)
Transformation ratio=K
As, (I')square.R'=(I2)square. R2
R'=(I2/I')square. R2
=(K)square. R2